Most plastic bags are discarded, often after a single use. Recycling of plastics after final use is possible, but plastic bags, in particular, are rarely recycled. According to the UK-based Ban the Bag campaigning group, 0.5% of plastic bags are recycled. Standard plastic bags may take between 500 and 1000 years to decompose, However, such figures are only ever estimates because plastics have not existed for long enough for the precise decomposition time to be measured.

Additives have been developed that allow plastic to degrade and biodegrade within a few months in landfill (as opposed to an estimated 500-1000 years for non-degradable plastic). Plastics made with these additives are called oxobiodegradable, and have been adopted by many 'ethical' retailers, e.g., the Co-op in the UK. However, some argue that oxo-biodegradable plastics contribute more to global warming as they release their carbon as carbon dioxide and methane far more quickly than plastics in landfill.

Polyethylene, (IUPAC name polyethene), is a thermoplastic commodity heavily used in consumer products (over 60 million tons are produced worldwide every year). It is a polymer consisting of long chains of the monomer ethylene (IUPAC name ethene).

High-density polyethylene (HDPE) is a polyethylene thermoplastic made from petroleum. It takes 1.75 kilograms of petroleum (in terms of energy and raw materials) to make one kilogram of HDPE. This compound is used to make plastic bags, and other products like detergent containers.Also used is: Low-density polyethylene (LDPE) is a thermoplastic made from oil. It was the first grade of polyethylene, produced in 1933 by Imperial Chemical Industries (ICI) using a high pressure process via free radical polymerisation. Its manufacture employs the same method today. This compound is used in plastic bags and other plastic products like six-pack soda can rings.

Comments

Thank you for the comment. I dug and shouted it to my friends. I have been learning more recently about biodegradable items in the landfill that get buried under nonbio and give off methane gas. For years I thought, why not put my food scraps into the garbage? I actually thought it would help the landfill decompose! Did you catch the BBC show Dumped, where they live at a landfill for three weeks?